Agreed, it would be best to supplement LED's with some T5 lighting since LED doesn't produce U.V. But the thing about LED which makes them better than MH for one is they use half the amount of energy, there is also no heat transfer to your tank, the results in growth and color have been amazing, you won't need to spend hundreds of dollars replacing bulbs every year, their reduction of output over the life of the bulb is way way better than MH so far less shift in spectrum and color. And done properly they can last you upto 10-12 years of average use.
Basically, they do cost a little more upfront and that's why there has been this revolution lately of people DIY'ing their own system because it's far less expensive. But once you factor in the cost of replacing MH bulbs each year, the heat that they produce, the energy that they consume and over all maintenance. LED's hands down are a better choice. If it wasn't for the fact of patenting issues in the U.S. there would be more companies producing these fixtures and prices could come down. But untill that happens then purchasing a plug and play system remains expensive.
Just to give you an idea...I'm about to build an LED array for my 120G. For about $1,000 I'll be able to replicate the same benefits of a fixture that costs around $3,500. I'll probably incorporate 2 T5 bulbs into the fixture for some supplimental lighting. But still far cheaper than MH over the long run.
